diff --git a/.classpath b/.classpath
index 9c6900895d..7d602704d8 100644
--- a/.classpath
+++ b/.classpath
@@ -1,9 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
-	<classpathentry kind="src" path="JavaSource"/>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-17">
+	<classpathentry excluding="**" kind="src" output="target/classes" path="JavaSource">
 		<attributes>
-			<attribute name="module" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+			<attribute name="optional" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-11">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
 		</attributes>
 	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.jst.j2ee.internal.web.container"/>
@@ -15,7 +20,44 @@
 	<classpathentry kind="src" path="target/generated-sources/annotations">
 		<attributes>
 			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+			<attribute name="ignore_optional_problems" value="true"/>
+			<attribute name="m2e-apt" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" output="target/classes" path="target/src">
+		<attributes>
+			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" output="target/test-classes" path="src/test/java">
+		<attributes>
+			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+			<attribute name="test" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry excluding="**" kind="src" output="target/test-classes" path="src/test/resources">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+			<attribute name="test" value="true"/>
+			<attribute name="optional" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" output="target/test-classes" path="target/generated-test-sources/test-annotations">
+		<attributes>
+			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+			<attribute name="ignore_optional_problems" value="true"/>
+			<attribute name="m2e-apt" value="true"/>
+			<attribute name="test" value="true"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry kind="output" path="WebContent/WEB-INF/classes"/>
+	<classpathentry kind="output" path="target/classes"/>
 </classpath>
diff --git a/.project b/.project
index cd5cfa3f6b..20b34782a6 100644
--- a/.project
+++ b/.project
@@ -25,12 +25,29 @@
 			<arguments>
 			</arguments>
 		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.m2e.core.maven2Builder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
 	</buildSpec>
 	<natures>
+		<nature>org.eclipse.m2e.core.maven2Nature</nature>
 		<nature>org.eclipse.jem.workbench.JavaEMFNature</nature>
 		<nature>org.eclipse.jdt.core.javanature</nature>
 		<nature>org.eclipse.wst.common.project.facet.core.nature</nature>
 		<nature>org.eclipse.wst.common.modulecore.ModuleCoreNature</nature>
 		<nature>org.eclipse.wst.jsdt.core.jsNature</nature>
 	</natures>
+	<filteredResources>
+		<filter>
+			<id>1777808862715</id>
+			<name></name>
+			<type>30</type>
+			<matcher>
+				<id>org.eclipse.core.resources.regexFilterMatcher</id>
+				<arguments>node_modules|\.git|__CREATED_BY_JAVA_LANGUAGE_SERVER__</arguments>
+			</matcher>
+		</filter>
+	</filteredResources>
 </projectDescription>
diff --git a/.settings/org.eclipse.jdt.core.prefs b/.settings/org.eclipse.jdt.core.prefs
index 5377a0d829..96c1b8bbba 100644
--- a/.settings/org.eclipse.jdt.core.prefs
+++ b/.settings/org.eclipse.jdt.core.prefs
@@ -13,12 +13,13 @@ org.eclipse.jdt.core.compiler.annotation.nullanalysis=disabled
 org.eclipse.jdt.core.compiler.annotation.owning=org.eclipse.jdt.annotation.Owning
 org.eclipse.jdt.core.compiler.annotation.resourceanalysis=disabled
 org.eclipse.jdt.core.compiler.codegen.methodParameters=do not generate
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=17
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
 org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
-org.eclipse.jdt.core.compiler.compliance=17
+org.eclipse.jdt.core.compiler.compliance=11
 org.eclipse.jdt.core.compiler.debug.lineNumber=generate
 org.eclipse.jdt.core.compiler.debug.localVariable=generate
 org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.ignoreUnnamedModuleForSplitPackage=enabled
 org.eclipse.jdt.core.compiler.problem.APILeak=warning
 org.eclipse.jdt.core.compiler.problem.annotatedTypeArgumentToUnannotated=info
 org.eclipse.jdt.core.compiler.problem.annotationSuperInterface=warning
@@ -119,6 +120,6 @@ org.eclipse.jdt.core.compiler.problem.unusedPrivateMember=warning
 org.eclipse.jdt.core.compiler.problem.unusedTypeParameter=ignore
 org.eclipse.jdt.core.compiler.problem.unusedWarningToken=info
 org.eclipse.jdt.core.compiler.problem.varargsArgumentNeedCast=warning
-org.eclipse.jdt.core.compiler.release=enabled
-org.eclipse.jdt.core.compiler.source=17
-org.eclipse.jdt.core.compiler.ignoreUnnamedModuleForSplitPackage=enabled
+org.eclipse.jdt.core.compiler.processAnnotations=enabled
+org.eclipse.jdt.core.compiler.release=disabled
+org.eclipse.jdt.core.compiler.source=11
diff --git a/JavaSource/org/unitime/timetable/util/DateUtils.java b/JavaSource/org/unitime/timetable/util/DateUtils.java
index 3109e5f09a..8dbd98e7cb 100644
--- a/JavaSource/org/unitime/timetable/util/DateUtils.java
+++ b/JavaSource/org/unitime/timetable/util/DateUtils.java
@@ -28,6 +28,9 @@
  */
 public class DateUtils {
     public static int getWeek(Date date) {
+		if (date == null) {
+    throw new IllegalArgumentException("Date cannot be null");
+}
     	Calendar c = Calendar.getInstance(Locale.US);
     	c.setTime(date);
     	int week = c.get(Calendar.WEEK_OF_YEAR);
@@ -37,6 +40,9 @@ public static int getWeek(Date date) {
     	return week;
     }
     public static int getDayOfYear(Date date) {
+		if (date == null) {
+    throw new IllegalArgumentException("Date cannot be null");
+}
     	Calendar c = Calendar.getInstance(Locale.US);
     	c.setTime(date);
     	return c.get(Calendar.DAY_OF_YEAR);